1. Field of the Invention
One embodiment of the present invention relates to a programmable logic device which can change the structure of hardware and a semiconductor device.
2. Description of the Related Art
In a programmable logic device (PLD), a logic circuit is composed of an adequate number of programmable logic elements (basic blocks), and the function of each programmable logic element and interconnections between the programmable logic elements can be changed after manufacture. Specifically, the PLD includes a plurality of programmable logic elements and a routing resource for controlling a connection between the programmable logic elements. The programmable logic element and the routing resource each include a register. The register stores circuit information (configuration data) for defining the function of each programmable logic element and a connection between the programmable logic elements formed by the routing resource.
A register for storing configuration data is called a configuration memory. Storing configuration data in a configuration memory is called configuration. In particular, rewriting the configuration memory with another configuration data is called reconfiguration.
Patent Document 1 discloses a programmable LSI which stores configuration data sent from a DRAM in a configuration memory composed of an SRAM to perform reconfiguration in a short time.